* Added Viterbi algorithm Fixes: #7465
Squashed commits
* [pre-commit.ci] auto fixes from pre-commit.com hooks
for more information, see https://pre-commit.ci
* Added doctest for validators
* moved all extracted functions to the main function
* Forgot a type hint
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
